Safety door-edge construction



April 18, 1967 N. K. MILLER SAFETY DOOR-EDGE CONSTRUCTION Filed April 4, 1966 ,wwf/vra?, NORMAN K. MILLER vvvvvvvvvvv 1 r l l t 4 l l f r n l r l r l n l 1 l l 1 r n l 1 r I l n l u t 1 l l. valli.

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United States Patent Oiice 3,315,050 Patented Apr. 18, 1967 3,315,050 SAFETY DGOR-EDGE CONSTRUCTION Norman K. Milier, Havertown, Pa., assignor to Miller Brothers, Upper Darby, Pa., a partnership Filed Apr. 4, 1966, Ser. No. 539,787 7 Claims. (Cl. 20G-61.43)

This invention relates generally to safety devices for closures, and is especially concerned with improvements in safety-edge constructions for power-operated doors, and the like.

It has been found highly advantageous to fabricate safety-edge constructions for doors and the like of relatively soft, resiliently yieldable material, such as plastic foam, say in the manner disclosed in my copending patent application Ser. No. 341,639, led Jan. 3l, 19.64. In addition to the protection afforded by such material to an obstruction engaged by the edge construction, the material is capable of being structurally formed in cooperative relation with desired actuating means to obtain a high degree of sensitivity and reliability, as for actuating an alarm, door-stopping device, or other. However, by the yieldability of the edge-construction material, it is susceptible to undue deformation or crushing, especially upon closure, but also in other instances. For example, a large overhead door having a safety-edge construction may, for long periods of time, have its entire weight resting upon and unduly deforming the safety edge. This is obviously undesirable in electrically operating safety-edge constructions wherein contacts may be deformed into permanent engagement, `as well as in pneumatically operating safety-edge constructions wherein air How may be obstructed or reduced.

Accordingly, it is an important object of the present invention to provide a safety-edge construction for poweroperated doors which overcomes the above-mentioned difficulties, while utilizing the `sensitivity and reliability of resiliently yieldable materials without subjecting the materials to undue deforming stresses.

While the improvement ofthe instant invention is illustrated in conjunction with a safety-edge construction including electrical actuating means, and will be described hereinafter with particular reference thereto, it is appreciated that the invention is well adapted -for use with safety-edge devices having pneumatic and hydraulic actuating means, as desired,

It is still another object of the present invention to provide a safety-edge construction for power-operated doors and the like having the advantageous characteristics mentioned in the preceding paragraph, which is extremely simple in structure, durable and reliable throughout a long useful life, and which can be economically manufactured and installed.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

In tho drawings:

FIGURE l is -a diagrammatic representation of a power-operated door including a safety-edge construction in accordance with the teachings of the present invention;

FIGURE 2 is a partial transverse sectional view taken generally along the line 2 2 of FIGURE 1, illustrating the safety-edge construction of the present invention, and greatly enlarged for clarity;

FIGURE 3 is a longitudinal sectional view of the safety-edge construction of FIGURE 2, taken generally along the line 3 3 thereof, and broken away for conservation of space; and

FIGURE 4 is a longitudinal sectional view taken generally along the line 4-4 of FIGURE 3.

Referring now more particularly to the drawings, and specifically to FIGURE 1 thereof, a closure or door is there generally designated 10, and may be of any suitable design, such as horizontal rolling, overhead, swinging, or other. The closing edge of the door 10 is provided with a safety-edge construction 11 in accordance with the teachings of the present invention, as will be described more fully hereinafter. An electrical operating circuit for powering the door 10 may include a motor 12 connected on one side through a conductor 13` to an on-oi switch 14 which is, in turn connected through a conductor 15 to one side of a power source 16. The other side of the power source 16 is connected by 4a conductor 17 to one side of a circuit breaker or normally closed relay 18, the other side of the relay being connected by a conductor 19 to the drive or motor 12. The circuit breaker 18 may include an energizing coil 20 having one end connected by a conductor 21 to the safety edge 11. The other end of coil 20 may be connected by a conductor 22 to one side of the power supply 16. The other side of the power supply 16 may be connected by a conductor 23 to the safety edge 11. Hence, upon closure of contacts of the safety edge 11, the coil 20 of circuit breaker 18 is energized to open the circuit breaker and disable the motor 12. Of course, suitable voltage reduction may be employed, if desired. As an optional alternative or n in addition to disabling of the drive 12 responsive to actuation by the circuit breaker 18, there may be provided suitable alarm, signal means or other, if desired. Also, it is understood that in place of or in addition to the electrically energized actuating relay or circuit breaker 18, actuation to disable the drive 12 may be accomplished by other suitable means, such as pneumatic or hydraulic.

Referring now to FIGURES 2-4, the safety edge 11 is there seen as extending along the closing edge 36 of the door 10. More specifically, the safety edge 11 may include an elongate strip or pad 31 fabricated of resiliently yieldable material, such as open-cell plastic or rubber foam and extending closely along, substantially coterminous with the door edge 30. The pad 31 may be considered as an inner pad, being proximate to the door 1t), and may be of generally rectangular cross-sectional configuration. Spaced outwardly from -the inner pad 31 is an elongate outer pad 32 extending longitudinally along and outwardly spaced from the inner pad. The outer pad 32 may also be advantageously fabricated of resiliently yieldable material, such'as open-cell foam, being substantially coextensive with the inner pad 31 and having its inner surface 33 spaced from and facing toward the outer surface 34 of the inner pad. -Interposed in sandwiched relation between the inner and outer pads 31 and 32 is an intermediate elongate strip or pad 35, which is also advantageously fabricated of resiliently yieldable material, such as open-cell plastic or rubber foam. The intermediate pad 35 may also be of a generally rectangular crosssectional configuration, having a lateral extent substantially equal to that of the inner and outer pads 311 and 32, so that the inner, outer and intermediate pads, in their assembled relationship, provide a generally rectangular cross-sectional configuration. It is preferred that opposite faces of the intermediate pad 35 be secured, as by adhesive, to the faces 33 and 34 of pads 32 and 31.

At longitudinally spaced locations along the intermediate pad 35, there are formed therein a series of elongate thru holes 36, each opening on opposite sides to the inner and outer pads 31 and 32. As thus far described, the inner, outer and intermediate pads 31, 32 and 35 may be considered as an elongate formation of resiliently yieldable material extending along the door edge 30.

Secured on the facing sides 33 and 34 of outer and inner pads 32 and 31 are elongate strips of exible, electrically conductive sheet material 38 and 39, as of aluminum. The conductive sheets 39 may extend the entire len-gth of the outer and inner pads 32 and 31, on respective facing surfaces 33 and 34, and may be advantageously secured thereto, as by adhesive, or the like. Thus, it will be apparent that opposed portions of the conductive sheets 38 and 39 will be exposed through the openings or holes 36 and presented to each other in spaced confronting relation through the openings.

An inner covering 40 of flexible, impermeable sheet material, such as of thermoplastic may be conformably engaged about the foam formation of pads 31, 32 and 35. In addition, an outer covering 41 may be conformably engaged about the inner covering 40, and may be fabricated of relatively high-strength, exible sheet material, such as vinyl-coated nylon. The inner covering 40 and outer covering `41 may be heat-sealed closed to provide an impervious flexible cover or casing for the foam formation 31, 32 and 35; and further, the casin-g may be pro- Ivided with tabs or extensions 42 and 43 for securement to the door 10.

The electrically conductive sheets or strips 38 and 39 may be connected to .the conductors 21 and 23, discussed in connection with FIGURE 1, and are movable into engagement with each other to make electrical contact, as when the edge construction 11 engages an obstacle. Such condition is .illustrated in FIGURE 3, wherein an obstacle imparts a force in the direction of arrow 45. The coil 2t) of FIGURE 1 is thereby energized to actuate circuit breaker 18 and disable motor 12.

In order to prevent excessive deflection of the foam formations 31, 32 and 35, there are provided therein a plurality of relatively hard limit members or blocks 46, 47 and 48. The limit members 46 and 48 are illustrated as being at opposite ends of the safety edge, and may suffice for relatively short safety-edge constructions, while a plurality of intermediate limit members 47 may be provided along relatively longer safety-edge constructions. The end limit members 46 and 48 may extend entirely through the inner pad 31, and the intermediate pad 35, so as to be of a thickness substantially equal to ther combined thicknesses of the inner and intermediate pads. In practice, the end limit members 46 and 48 may advantageously be fabricated of relatively hard rubber blocks, say of about 70-75 durometer. It will be appreciated that upon closing of a door having end limit members or blocks 46 and 48, even an overhead door, compression of the safety edge under the door weight is limited by the limit members. That is, crushing of the inner pad 31 and intermediate pad 35 is entirely prevented, while only relatively small end portions of the outer pad 32 are compressed. Further, the outer conductive strip or sheet 38 may extend the full length of the outer pad 32, and the inner conductive sheet or strip 39 may terminate at the end limit members or blocks 46 and 47, being continuous therebetween.

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An .intermediate limit member 47, which may also be fabricated of relatively hard rubber, say of 70-75 durometer, may extend entirely through the inner pad 31 and terminate at the electrically conductive sheet 39 so as to preserve the continuity thereof. A plurality of intermediate limit members or blocks 47 may be provided at spaced locations along the safety edge 11 to prevent excessive deection and deformation thereof, as by equipment caught by the door. As seen in FIGURE 4, the intermediate limit member or block 47 is of a lateral extent less than that of the inner pad 31, but could be of greater or less lateral dimension, as desired. Similarly, the dimensions of the end limit members 46 and 48 may be other than as illustrated, without departing from the instant invention. Also, intermediate limit members ot blocks 47 may be located opposite openings 36 in the intermediate pad 35, so as to limit compression of the intermediate pad as well as limit compression of the inner pad upon engagement of the edge construction 11 with an obstacle.

From the foregoing, it is seen that the present invention provides a safety-edge construction for power-operated doors and the like which fully accomplishes its intended objects and is well adapted to meet practical conditions of manufacture, installation and use.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, lit is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. A safety edge for a power-operated door, comprising an elongate generally straight formation of resiliently yieldable material adapted to extend along a door edge, said formation having at least one internal hollow, actuating means connected between said internal hollow and a device to be actuated upon localized transverse compression of said formation to close said hollow, a flexible cover conformably and hermetically encasing said formation and adapted for securement to a door, and a spaced pair of relatively stiff limit means extending at least partially through said formation for limiting transverse compression of said cover and formation over the entire length thereof to prevent rupture of said cover and operation of said actuating means upon door closure.

2. A safety-edge construction according to claim 1, said formation being fabricated 0f open-cell foam material for absorbing air from said hollow upon closure of the latter, and said `limit means limiting the displacement of uid from said foam material to prevent rupture of said cover and assure rapid return of said formation from its deformed condition.

3. A safety-edge construction according to claim 1, said limit means being located adjacent to opposite ends of said formation for limiting deformation upon closing of the door against a jamb or the like.

4. A safety-edge construction according to claim 1, said limit means comprising a plurality of spaced blocks having characteristics of hard rubber.

5. A safety-edge construction according to claim 1, said formation comprising an elongate resiliently compressible inner pad adapted to extend adjacent to the door edge, an elongate resiliently compressible outer pad extending along and in outwardly spaced facing relation with respect to said inner pad, an elongate resiliently compressible intermediate pad sandwiched between said inner and outer pads, said intermediate pad being formed with a series of thru openings spaced longitudinally thereof and defining said .internal hollows, and said limit means extending at least through said inner pad to limit deformation thereof upon closure of a door against a jamb or the like.

6. A safety-edge construction according to claim 5, said limit means extending through said intermediate pad 5 6 as Well as said inner pad to prevent undesired closing References Cited by the Examiner of said holiows. UNITED STATES PATENTS 7. A safety-edge construction according to claim 6, 1,915,292 6/1933 Conklin 200 86 said actuating means comprising a pair of exible elec- 3,133,167 5/ 1964 Miller ZOO- 61.43

5 trically conductive sheets on the facing sides of said inner FOREIGN PATENTS and outer pads spaced apart by said intermediate pad 122 351 12/1958 Russia and presenting opposed portions to each other through i said openings, for Contact of said opposed sheet portions BERNARD A. GILHEANY, Primary Examiner.

upon local transverse compression of said pads. 10 j' J BAKER, H. B. GILSON ASSI- mmf Examl-ers- 

1. A SAFETY EDGE FOR A POWER-OPERATED DOOR, COMPRISING AN ELONGATE GENERALLY STRAIGHT FORMATION OF RESILIENTLY YIELDABLE MATERIAL ADAPTED TO EXTEND ALONG A DOOR EDGE, SAID FORMATION HAVING AT LEAST ONE INTERNAL HOLLOW, ACTUATING MEANS CONNECTED BETWEEN SAID INTERNAL HOLLOW AND A DEVICE TO BE ACTUATED UPON LOCALIZED TRANSVERSE COMPRESSION OF SAID FORMATION TO CLOSE SAID HOLLOW, A FLEXIBLE COVER CONFORMABLY AND HERMETICALLY ENCASING SAID FORMATION AND ADAPTED FOR SECUREMENT TO A DOOR, AND A SPACED PAIR OF RELATIVELY STIFF LIMIT MEANS EXTENDING AT LEAST PARTIALLY THROUGH SAID FORMATION FOR LIMITING TRANSVERSE COMPRESSION OF SAID COVER AND FORMATION OVER THE ENTIRE LENGTH THEREOF TO PREVENT RUPTURE OF SAID COVER AND OPERATION OF SAID ACTUATING MEANS UPON DOOR CLOSURE. 